RFLP mapping of a major bruchid resistance gene in mungbean (Vigna radiata, L. Wilczek)

Abstract

Bruchids (genus Callosobruchus) are among the most destructive insect pests of mungbeans and other members of the genus, Vigna. Genetic resistance to bruchids was previously identified in a wild mungbean relative, TC1966. To analyze the underlying genetics, accelerate breeding, and provide a basis for map-based cloning of this gene, we have mapped the TC1966 bruchid resistance gene using restriction fragment length polymorphism (RFLP) markers. Fifty-eight F2 progeny from a cross between TC1966 and a susceptible mungbean cultivar were analyzed with 153 RFLP markers. Resistance mapped to a single locus on linkage group VIII, approximately 3.6 centimorgans from the nearest RFLP marker. Because the genome of mungbean is relatively small (estimated to be between 470 and 560 million base pairs), this RFLP marker may be suitable as a starting point for chromosome walking. Based on RFLP analysis, an individual was also identified in the F2 population that retained the bruchid resistance gene within a tightly linked double crossover. This individual will be valuable in developing resistant mungbean lines free of linkage drag.

Molecular Evolution and Phylogenetic Implications of Internal Transcribed Spacer Sequences of Nuclear Ribosomal DNA in the Phaseolus–Vigna Complex

“…This is all the more important in the context of their susceptibility to various pests and diseases, resulting in low and variable yields (Smartt, 1990) and low levels of genetic variability (Kaga et al, 1996;Baudoin and Maréchal, 1988;Smartt, 1990). The closely related wild diploid species, on the other hand, have wide genetic diversity and possess agronomically useful characters of importance (Young et al, 1992;Baudoin and Maréchal, 1985).…”

Role of Genomic tools for Mungbean [Vigna radiata (L.) Wilczek] improvement

“…Not many genetic markers were developed specifically for mungbean or blackgram. Restriction fragment length polymorphism (RFLP) markers of both cDNA and random genomic clones of mungbean were reported (Young et al, 1992). These RFLPs together with those from common bean [Phaseolus vulagris (L.)], cowpea [V. Unguiculata L. Walps] and soybean [Glycine max (L.) Merr.]…”

Construction and Characterization of a Lipotes vexillifer Genomic DNA BAC Library

“…To test this directly, we sought to identify only four nuclear genes that have been identified in L. vexillifer. Since genetic markers that can be used as probes to screen the library, such as RFLPs (restriction fragment length polymorphisms) (Young et al, 1992;, ESTs (expressed sequence tags) (Lijavetzky et al, 1999), or microsatellites (Allouis et al, 2001), are lacking, we designed primers to screen for the four genes by PCR. Our analysis revealed the presence of all four genes, demonstrating the utility of this library for the discovery of new genes.…”